1. Field of the Invention
The invention relates to the sheet discharging portion of an image forming apparatus such as a printer, and the construction of the sheet discharging portion of a sheet post-treating apparatus connected to the image forming apparatus.
2. Description of the Related Art
The discharging portion of an image forming apparatus or a sheet post-treating apparatus has a stacking tray for stacking discharged sheets thereon, and the stacking tray is usually inclined so that the downstream side thereof with respect to a sheet discharging direction may be above.
This intends to cause discharged sheets to slide down on the stacking tray in a direction opposite to a conveying direction after they are stacked on the stacking tray, and cause the trailing ends of the sheets to strike against a stacking wall provided on the upstream side of the tray, thereby snugly aligning the sheets in their stacked state and improving their outward appearance and handling property.
Also, like the invention described in Japanese Patent Application Laid-Open No. 2001-72302, there has been an apparatus provided with a stack height detecting lever provided so as to abut against the uppermost surface of sheets in order to detect the height of the sheets stacked on a stacking tray, and a sheet presence or absence detecting lever designed to protrude from the stacking tray and abut against the underside of the sheets, and be operated by the gravity of the sheets.
In the invention described in Japanese Patent Application Laid-Open No. 2001-72302, however, for each of the detecting lever for detecting the stack height and the detecting lever for detecting the presence or absence of the sheets, a sensor for detecting the position of the lever and a cable therefor becomes necessary, and this has caused an increase in cost.